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AR# 14332

4.2isp1 Timing - Tdcmino has changed between 4.2i and 4.2.01i


General Description:

I run the same NCD and PCF through 4.2i and 4.2.01i, yet the timing report shows that Tdcmino is different between the two. What can I do to fix this?


The difference is that the DCM fixed-phase shift is no longer calculated within the Tdcmino value; rather, it is accounted for as phase. This change was necessary because accounting for the fixed-phase as delay caused problems when an attempt was made to relate registers through the fixed phase -- the tool would report egregious hold violations.

Regrettably, this solution is not without its drawbacks. In this case, the PCF must be regenerated (via NGDBuild and MAP) within the new release in order to regenerate the PERIOD constraints with the proper phase relationships.

Therefore, to work around this problem, you must regenerate the implementation files through NGDBuild and MAP.

AR# 14332
Date Created 08/29/2007
Last Updated 01/18/2010
Status Archive
Type General Article